In recent years, mobile handsets (such as cellular phones and PDAs) have become more powerful and now offer additional functionality beyond just voice communication. For instance, many mobile handset devices today allow users to perform web browsing on the Internet, receive emails, and play video and audio content streamed from over a wireless network. Such devices contain increasingly powerful processors and enhanced video and audio capability. However, their storage capacity is generally much smaller than the capacity of PCs and notebook computers. As a result, users of mobile handsets are reliant upon video and audio content that is streamed rather than downloaded and stored permanently. The mobile handsets also tend to have relatively small buffers in which to store the streamed data before it is played on the mobile handset.
If a mobile handset user wishes to stop listening to streamed audio content or watching streamed video content while the content is still playing, then the mobile handset will stop playing the content and will inform the source of the streaming data (usually a server connected to the wireless network) to stop streaming the data. It would be desirable for the server or other source device to be able to keep track of the user's location (e.g., the number of bits from the beginning of the content, amount of time that elapsed since the content began playing, or some other measure) within the content when he or she stops the content, so that the user can continue playing the data at the same location at a later time.
Digital content often is broken into sub-sections (e.g., chapters in a DVD movie) by the provider of the source content. Under current mobile handset technology, if a user wishes to begin playing the content at a place other than the beginning section, then the mobile handset must first begin playing at the beginning section and then move to the desired section and begin playing at the desired section. It takes approximately 15 seconds to begin playing any given section (which corresponds to the time it takes to fill the buffer in the mobile handset with data), so the end result in this scenario is that the user will need to wait approximately 30 seconds before he or she can begin listening to or watching the desired section. It would be desirable for a user to be able to begin listening to or watching any section of the content with only one buffer delay instead of two.